AN EXPERIMENTAL STUDY ON THE AEROELASTIC STABILITY OF THIN CYLINDRICAL SHELLS AT THE LOWER SUPERSONIC MACH NUMBERS.
Final technical rept., 1 Nov 64-30 Oct 66,
MIDWEST RESEARCH INST KANSAS CITY MO
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During the initial phases of the test static pressure and boundary layer profile surveys were made over a rigid instrumented shell mounted in the position normally occupied by the flutter shells. The model boundary layer control system was also checked. In the final test phase the aeroelastic stability of five thin shells was investigated with the shells loaded under an axial compressive force andor internal pressure. A highly divergent panel flutter instability occurred on all of the models tested, each shell being destroyed within less than a second. High speed motion pictures were taken during the flutter of three of the shells. These pictures revealed that the initial instability appeared either in the form of a local dimple or in the form of a wave traveling in the free stream direction. The characteristic wave lengths of these initial instabilities were small compared to the shell radius and length. A comparison of the present experimental results with some earlier studies conducted at the higher supersonic Mach numbers indicates that the critical ratio of dynamic pressure to bending stiffness required to induce flutter is approximately three times that found at the higher Mach numbers. Considerable disagreement was also observed between these experimental results and the results of two different theoretical analyses. Author
- Fluid Mechanics